A note on approximate strengths of edges in a hypergraph

نویسندگان

  • Chandra Chekuri
  • Chao Xu
چکیده

Let H = (V, E) be an edge-weighted hypergraph of rank r. Kogan and Krauthgamer [7] extended Benczúr and Karger’s [2] random sampling scheme for cut sparsification from graphs to hypergraphs. The sampling requires an algorithm for computing the approximate strengths of edges. In this note we extend the algorithm for graphs from [2] to hypergraphs and describe a near-linear time algorithm to compute approximate strengths of edges; we build on a sparsification result for hypergraphs from our recent work [4]. Combined with prior results we obtain faster algorithms for finding (1+ǫ)approximate mincuts when the rank of the hypergraph is small.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

On the maximum number of edges in a hypergraph with a unique perfect matching

In this note, we determine the maximum number of edges of a k-uniform hypergraph, k ≥ 3, with a unique perfect matching. This settles a conjecture proposed by Snevily.

متن کامل

The Complexity of Finding Arborescences in Hypergraphs

Basic definitions. For X a finite set of vertices, a hypergraph H on X is a family of subsets (called edges) of X. In a directed hypergraph H, every set h E H contains a distinguished element called the head of h (a set h may appear more than once in H but with different heads). A hypergraph H’ is a subhypergraph of H iff H’ c H. A directed hypergraph H is an arborescence iff (i) H is empty, or...

متن کامل

A note on packing of two copies of a hypergraph

A 2-packing of a hypergraph H is a permutation σ on V (H) such that if an edge e belongs to E(H), then σ(e) does not belong to E(H). We prove that a hypergraph which does not contain neither empty edge ∅ nor complete edge V (H) and has at most 12n edges is 2-packable. A 1-uniform hypergraph of order n with more than 1 2n edges shows that this result cannot be improved by increasing the size of H.

متن کامل

A note on the Erdos-Farber-Lovász conjecture

A hypergraph H is linear if no two distinct edges of H intersect in more than one vertex and loopless if no edge has size one. A q-edge-colouring of H is a colouring of the edges of H with q colours such that intersecting edges receive different colours. We use ∆H to denote the maximum degree of H. A well known conjecture of Erdös, Farber and Lovász is equivalent to the statement that every loo...

متن کامل

On the Pixel Expansion of Hypergraph Access Structures in Visual Cryptography Schemes

In a visual cryptography scheme, a secret image is encoded into n shares, in the form of transparencies. The shares are then distributed to n participants. Qualified subsets of participants can recover the secret image by superimposing their transparencies, but non-qualified subsets of participants have no information about the secret image. Pixel expansion, which represents the number of subpi...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • CoRR

دوره abs/1703.03849  شماره 

صفحات  -

تاریخ انتشار 2017